Java Reference
In-Depth Information
Display 18.19
Some Methods in the Class
Color
(part 2 of 2)
public
Color(
float
r,
float
g,
float
b)
Constructor that creates a new
Color
with the specified RGB values. The parameters
r, g
, and
b
must each be in the range
0.0
to
1.0
(inclusive).
public int
getRed()
Returns the red component of the calling object. The returned value is in the range
0
to
255
(inclusive).
public int
getGreen()
Returns the green component of the calling object. The returned value is in the range
0
to
255
(inclusive).
public int
getBlue()
Returns the blue component of the calling object. The returned value is in the range
0
to
255
(inclusive).
public
Color brighter()
Returns a brighter version of the calling object color.
public
Color darker()
Returns a darker version of the calling object color.
public boolean
equals(Object c)
Returns
true
if
c
is equal to the calling object color; otherwise, returns
false
.
PITFALL: Using
doubles
to Define a Color
Suppose you want to make a color that is made of half the possible amount of red,
half the possible amount of blue, and no green. The following seems reasonable:
Color purple =
new
Color(0.5, 0.0, 0.5);
However, this will produce a compiler error. The numbers
0.5
and
0.0
are considered
to be of type
double
, and this constructor requires arguments of type
float
(or of
type
int
). So, an explicit type cast is required, as follows:
Color purple =
new
Color((
float
)0.5, (
float
)0.0, (
float
)0.5);
Java does allow the following method of specifying that a number is of type
float
,
which can be simpler than the previous line of code:
Color purple =
new
Color(0.5f, 0.0f, 0.5f);
(continued)